Problem(s) Encountered:

At ~3am, slew error had occurred when I tried to move to Az~88, Alt~51.  After that, TCS and JSkyCalc could not control the telescope. 

Slew ERROR  with tracking OFF

When I tried to move to Zenith, ERROR point not converging dist=39.875 dra=319.111 ddec=20.856 

When I tried to close mirror cover, ERROR mirror mirror both open and closed 

The 2.4m observer tried to solve the problem from 4:30, but failed.

Fortunately dome closed well, but we could not stow the telescope to Zenith.

Solution:

Found the dec controller indicating error.  Reset that and all telescope motion returned.  I did also note that system was left in an odd state where everything needed to be homed.  So I homed everything and zeroed out errors.